A flat cable 1 is a flexible cable wherein a plurality of flat conductors 1a are arranged in parallel and insulated with an insulation 1b as shown in FIGS. 16 and 18. A terminal 3 comprises a substrate 3a of a width W11 and a plurality of cramp pieces 3b˜3d which project alternately on the opposite sides of the substrate 3a as shown in FIG. 17.
Conventionally, the flat cable 1 and the terminal 3 are electrically connected as follows: As shown in FIG. 16, a cramp 5 having a bending concave portion 5a is placed under an intended flat conductor 1a. Then, a terminal 3 is placed just over the intended flat conductor 1a, being guided by positioning walls 6 as shown in FIG. 16. The terminal 3 is then stuck into the intended flat conductor 1a by pressing the terminal 3 with a pressing member 7 from above. The cramp pieces 3b˜3d that have been stuck through the flat cable 1 are bent inward, i.e., toward each other by the bending concave portion 5a of the cramp 5 as shown in FIG. 18. As a result, the terminal 3 is electrically connected with the intended flat conductor 1a of the flat cable 1.
This way of connecting the flat cable 1 and the terminal 3 is usable when the flat cable 1 has a flat conductor 1a of, for example, 0.15 mm in thickness and more than 3 mm or so in width.
However, in recent years, a flat cable having a flat conductor of, for example, 0.15 mm in thickness and 1.5˜2.0 mm or so in width has come into use in complicated wiring circuits. When a flat cable has a small conductor-width as above, a small terminal whose substrate-width is 1.2 mm or so corresponding to the conductor-width is used.
In the small conductor as above, cramp pieces are smaller in size and rigidity than those of an ordinary terminal, and therefore easily buckle when they are stuck into a flat cable.
The cramp pieces that have buckled cannot form stable curves as shown in FIG. 18. This causes a problem that stable electrical connection with little variation in contact resistance cannot be formed between the terminal and a flat conductor.
In addition, since the small terminal is small in rigidity, it cannot be used for connecting small-width flat conductors 1a of flat cables that are crossed.
An object of the present invention is to provide a method of connecting a flat cable and a terminal wherein a flat conductor and cramp pieces can be connected stably with little variation in contact resistance.
Another object of the present invention is to provide a method of connecting a flat cable and a terminal wherein a larger area of contact between cramp pieces and a flat conductor can be ensured, so that a stable electrical connection can be formed.
Another object of the present invention is to provide a method of connecting a flat cable and a terminal wherein cramp pieces can be surely stuck through flat conductors when a plurality of terminals should be connected to a plurality of flat conductors, respectively.
Another object of the present invention is to provide a method of connecting a flat cable and a terminal wherein cramp pieces can be stuck through flat conductors of flat cables placed one on another, without buckling.
Another object of the present invention is to provide a method of connecting a flat cable and a terminal wherein cramp pieces can be stuck through flat conductors of flat cables placed one on another, without buckling, and a larger area of contact between the cramp pieces and the flat conductors can be ensured, so that a stable electrical connection can be formed.
Another object of the present invention is to provide a method of connecting a flat cable and a terminal wherein terminals can be connected to flat conductors of flat cables placed one on another, without cramp pieces buckling, and the cramp pieces can be surely stuck through corresponding flat conductors.